I never owned a braked rifle the first 35 years of shooting. Two years ago I had brakes installed on two rifles, a 300 Win Mag and a 338 Edge. Everything about the brakes is a positive except the additional noise, and the extended barrel length. If your gunsmith is local, you could always try it without a brake first, and then if you're unhappy with it, have the brake installed later. The additional fee to install one after the fact wouldn't be too great. Ask your gunsmith about the difference in cost. If you've never shot a rifle with a muzzle brake
, I would recommend trying one. Maybe your gunsmith has a braked rifle he could let you shoot a couple times. That might help you decide. They're pretty darn nice.
I now prefer a brake if the rifle kicks very much. 140 grain bullets out of the varmint weight 7mm STW shouldn't kick terribly bad. 180s would kick more and get to about the point where I'd prefer a brake. If you're not going to pack the rifle around through the woods and brush alot, you might go with the muzzle brake right from the get go. They do make shooting the rifle more enjoyable, and I think many people will shoot better if they get kicked less.
I shoot 8 1/2 lb 7mm Rem Mags with 168gr Bergers with no brakes and they're OK. But the recoil is just about to the point where a muzzle brake would be nice. I can't see bullet hits even at long range with either of my 7mm Rem Mags because they jump too much under recoil.